add base of watcher

pkg/watcher/types.go

@@ -0,0 +1,8 @@
+package watcher
+
+import "errors"
+
+var (
+	ErrNilProvider = errors.New("provider can't be nil")
+	ErrNilHTTP     = errors.New("http can't be nil")
+)

pkg/watcher/watcher.go

@@ -0,0 +1,47 @@
+package watcher
+
+import (
+	"github.com/datahearth/ddnsclient/pkg/http"
+	"github.com/datahearth/ddnsclient/pkg/providers"
+	"github.com/datahearth/ddnsclient/pkg/utils"
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/viper"
+)
+
+type Watcher interface {
+	Run() error
+}
+
+type watcher struct {
+	logger     logrus.FieldLogger
+	provider   providers.Provider
+	http       http.HTTP
+	subdomains []string
+	domain     string
+}
+
+func NewWatcher(logger logrus.FieldLogger, provider providers.Provider, http http.HTTP) (Watcher, error) {
+	if logger == nil {
+		return nil, utils.ErrNilLogger
+	}
+	if provider == nil {
+		return nil, ErrNilProvider
+	}
+	if http == nil {
+		return nil, ErrNilHTTP
+	}
+	domain := viper.GetStringMap("watcher")["domain"].(string)
+	subdomains := utils.AggregateSubdomains(viper.GetStringMap("watcher")["subdomains"].([]string), domain)
+
+	return &watcher{
+		logger:     logger,
+		provider:   provider,
+		http:       http,
+		domain:     domain,
+		subdomains: subdomains,
+	}, nil
+}
+
+func (w *watcher) Run() error {
+	return nil
+}